If they could commit to just five seasons it could be a really good show, but if they plan to try to keep it going and milk it, it'll be complete garbage by season 3
It's how the games are though. The different Fallout games exist in The same universe, but don't involve the same characters every time. I'd love it to be a combo, do 2 or 3 seasons of this set of characters. Tell their story. Then do Fallout: Alaska or whatever, a completely separate series, with a tie-in or two.